Chapter 8

Question 1

What are the three parts of the Cell Theory?

Answer 1

1. All living things are made of cells.
2. The cell is the basic unit of life.
3. All cells come from pre-existing cells.

Question 2

Who contributed to the development of the Cell Theory?

Answer 2

Schleiden (plants), Schwann (animals), and Virchow (pre-existing cells).

Question 3

What is a unicellular organism? Give examples.

Answer 3

A single-celled organism that performs all life functions. Examples: Amoeba, E. coli.

Question 4

What is a multicellular organism? Give examples.

Answer 4

An organism made of many specialized cells. Examples: Humans, plants.

Question 5

What are the main functions of cells?

Answer 5

Metabolism, growth and repair, response to environment, and reproduction.

Question 6

What organelle makes energy for the cell?

Answer 6

Mitochondria – converts food into ATP.

Question 7

How do eukaryotic cells reproduce?

Answer 7

By mitosis.

Question 8

How do prokaryotic cells reproduce?

Answer 8

By binary fission.

Question 9

What is mitosis

Answer 9

makes 2 new body cells, identical to the og cell

Question 10

What is meiosis

Answer 10

Makes 4 sex cells. different from the og cell. Chromosones are half the original (either 2 X, or 1 X and 1 Y

Question 11

What is binary fission

Answer 11

one cell splits into two identical ones (in prokaryotes)

Question 12

What does DNA do in cells?

Answer 12

Contains genetic instructions for growth, protein synthesis, and reproduction.

Question 13

What are the two types of metabolic reactions?

Answer 13

Catabolic (breakdown, releases energy) and anabolic (build-up, uses energy).

Question 14

What is the function of the nucleus?

Answer 14

Stores DNA and controls cell activities.

Question 15

What is the function of mitochondria?

Answer 15

Produces ATP through cellular respiration.

Question 16

What is the function of ribosomes?

Answer 16

Makes proteins by assembling amino acids.

Question 17

What is the difference between a light microscope and an electron microscope?

Answer 17

Light microscopes use visible light; electron microscopes use electrons for higher resolution.

Question 18

What are TEM and SEM used for? (both types of electron microscopes)

Answer 18

TEM: internal structures; SEM: surface details.

Question 19

Why are staining techniques used in cell study?

Answer 19

To add contrast and highlight structures.

Question 20

What is cell fractionation?

Answer 20

Breaking cells and centrifuging to separate organelles.

Question 21

Why are cells small?

Answer 21

To maintain a high surface area-to-volume ratio for efficient transport.

Question 22

If a cell is too large, do processes slow down because it has more mass now?

Answer 22

Yes
-Surface area to volumes goes DOWN
- nutrients and waste move too slowly (diffusioin)
- less efficient

Question 23

What makes up most of a cell’s mass?

Answer 23

Water (~70%).

Question 24

What are the four main types of macromolecules in cells?

Answer 24

Carbohydrates, Lipids, Proteins, Nucleic acids

Question 25

What are the roles of inorganic ions in cells?

Answer 25

Maintain pH, transmit signals, and serve as enzyme cofactors.

Question 26

What are the main differences between prokaryotic and eukaryotic cells?

Answer 26

: Prokaryotes: no nucleus or membrane-bound organelles; small and simple. Eukaryotes: have nucleus and organelles; larger and more complex.

Question 27

What does the endosymbiotic theory propose?

Answer 27

Some organelles (like mitochondria and chloroplasts) originated from free-living prokaryotes that were engulfed by larger cells.

Question 28

What evidence supports the endosymbiotic theory?

Answer 28

Mitochondria and chloroplasts have circular DNA, divide by binary fission, and have prokaryote-like ribosomes.

Question 29

What was the oxygen revolution?

Answer 29

The buildup of oxygen from cyanobacteria’s photosynthesis, enabling aerobic respiration and complex life.

Question 30

how did multicellularity evolve?

Answer 30

Unicellular → colonial → specialized multicellular organisms.

Question 31

Are viruses living?

Answer 31

No, they are acellular and only reproduce inside a host cell.

Question 32

What are the main parts of a virus?

Answer 32

Nucleic acid (DNA or RNA), capsid (protein coat), and sometimes a lipid envelope.

Question 33

What are the five stages of viral infection?

Answer 33

Attachment, penetration, biosynthesis, maturation, and lysis/release.

Question 34

What are key features of bacteria?

Answer 34

Prokaryotic, have a peptidoglycan cell wall, reproduce by binary fission.

Question 35

What are the shapes of bacteria?

Answer 35

Cocci (spherical), bacilli (rod-shaped), spirilla (spiral).

Question 36

Give examples of bacteria.

Answer 36

E. coli, Staphylococcus aureus, Cyanobacteria.

Question 37

What happens in attachment?

Answer 37

the virus sticks to the host cell by matching with special receptors.

Question 38

What happens in penetration?

Answer 38

The virus or its genetic material enters the host cell. How: By fusing with the membrane or being swallowed (endocytosis).

Question 39

What happens in biosynthesis?

Answer 39

The virus takes over the cell and makes copies of its DNA or RNA and proteins.

Question 40

What happens in maturation?

Answer 40

The new virus parts are put together to form complete viruses.

Question 41

What happens in lysis and release?

Answer 41

The host cell breaks open and new viruses come out to infect other cells.

Question 42

How are archaea different from bacteria?

Answer 42

Lack peptidoglycan; have ether-linked membranes; live in extreme environments.

Question 43

What are examples of archaea?

Answer 43

Methanobrevibacter, Halobacterium, Sulfolobus.

Question 44

What environments do archaea thrive in?

Answer 44

Extreme conditions like hot springs, salt lakes, or anaerobic environments.